Method and apparatus for making carbonyl iron



June 5, 1945- J. v. FILL 2,377,486

METHOD AND APPARATUS ,FOR MAKING- CARBONYL IRON 7 Filed May 22, 1941 INVENTOR ATTORNEY$ Patented June 5, 1945 METHOD AND APPARATUS FOR. MAKING OARBONYL IRON John V. Fill, Dobbs Ferry, N. Y., assignor to Micro Products Corporation, Dover, Del., a corporation of Delaware ApplicationMay 22, 1941, Serial No. 394,658

'4 Claims.

This invention relates to a method and apparatus for making carbonyl iron for use in magnetic cores for radio apparatus and the like.

The extremely minute particles of iron which are deposited in the thermal decomposition of ferro-pentacarbonyl have proved highly desirable for use in making magnetic cores. In order to be most perfectly adaptedlfor this purpose the minute iron particles should consist of spherical shells of decreasing thickness.

I found that the form of the iron particles depends upon the pressure and concentration of the iron carbonyl gas during the decomposition thereof and that to obtain-the particles in the best possible form the pressure and concentration of the carbonyl gas should be reduced dur ing the decomposition. This results in causing the iron to deposit in layers on nuclei which are formed when the gas is at high pressure and concentration. The layers become thinner as the concentration and pressure decrease.

My invention provides a continuous method of decomposing iron carbonyl under conditions of decreasing pressure and decreasing concentration. This is accomplished in accordance with the invention by introducing compressed gaseous ferro-pentacarbonyl into the upper part of a tapering chamber. The decomposition occurs as the gas and the deposited particles move downwardly in the chamber. movement the concentration and pressure of the gas decrease with the evolution of carbon momoxide gas and the increase in the cross section of the chamber.

In order that my invention may be clearly understood, I will describe in detail a method embodying the invention carried out in the apparatus embodying the invention which is shown in the accompanying drawing in which,

Fig. 1 is a sectionalelevation of the apparatus for directing. gas from the larger end of the,

inner chamber into the smaller end of the outer chamber. Vertical pipes 9 extend from outlet openings in the bottom of the outer chamber 4 In this downward to collectors I0 provided with gas vents l2. The

chamber 4 is provided with a heating jacket 5,

and the pipes 9 may be provided with cooling coils H. An inlet pipe I is connected to the lower end of the inner chamber 2.

In carrying out my method my means of this apparatus a high temperature is maintained in the chambers 2 and 4, and liquid ferro-pentacarbonyl is introduced into the inner chamber 2 through the pipe I at such a rate that the liquid is converted into a gas but is not decomposed as it rises through-the inner chamber 2. The volatilization of the liquid creates pressure so that gaseous carbonyl under considerable pressure enters the upper end of the outer chamber 4. As the carbonyl gas descends in the chamber 4 it decomposes into iron and carbon monoxide gas. Because of the diverging walls of the chamber 4 the carbonyl is decomposedunder conditions of decreasing pressure and decreasing concentration so that the iron is deposited in thinner and thinner layers on the nuclei which have formed at or near the top of the chamber 4. The iron particles formed in the chamber 4 fall through the pipes 9 into the collectors I 0. The carbon monoxide gas formed in the decomposition, whose volume is somewhat reduced by the cooling coils II, passes into the collectors Ill and out through the pipes l2 whence it may be conducted to an apparatus for makin ferropentacarbonyl. I

The temperature in the chamber 4 is indicated by thermo-couple 8., Supply of heating medium to the jacket is most desirably regulated so as to maintain the temperature in the chamber 4 at approximately 200 F.

It is not essential that the carbonyl move upwardly while it is being converted into a gas. Thus, while the apparatus which has been shown in Fig. 1 is compact and convenient it may be modified by inverting the inner-chamber 2 and placing it on top of the outer chamber 4 so that the two chambers become a single conical chamber with its larger end downward, as shown in Fig. 2. The chamber may be in the form of a prism instead of a cone, or may take the form of an ellipsoid of revolution, as shown in Fig. 3.

What I claim is:

r. 1. The method of making carbonyl iron which consists in thermal decomposition of ferropentacarbonyl under conditions of increasing volume, decreasing concentration and decreasing pressure.

2. The method of making carbonyl iron which consists in causing compressed ierro-pentacarbonyl gas to move downwardly in a heated I chamber whose walls diverge so that the hori- 2 aavmae zontal cross section oi the chamber increases downwardly, so that thermal decomposition of the term-carbonyl occurs under conditions of de- 4. Apparatus for making carbonyl iron comprising an inner conical chamber with its larger end upward and an outer conical chamber with its larger end downward, baiiles for directin gas from the larger end of the inner chamber into the smaller end of the outer chamber, an inlet pipe at the smaller end of the inner chamber, outlet pipes at the larger end 01 the outlet chamber and a heating Jacket around the outer cham- JOHN V. FILL.

ber. 

